File system is the structure in which files are stored on the hard drive. In Mac we have HFS, HFS+ and FAT file systems. When data is stored on Mac then it gets stored in different sectors of hard drive. So whenever problem arises in the file systems you may face some specific symptoms like:
- Mac OS X not booting up.
- When you switch on a Mac, the systems starts-up and then shutdown in between the loading process.
- Mac suddenly shuts down when you are working on it.
If these types of problems are occurring in your Mac then there is a strong possibility that file system of Mac has corrupted and you may not be able to access hard drive of your Mac.
Sometimes while trying to access the volume you may get this error:
“-123 wrgVolTypErr Not an HFS volume [wrong volume type error or (obsolete) operation not supported for MFS]”.
How to solve this problem?
To heal this error you can follow the below mentioned methods:
- First start Mac in safe mode by pressing the shift key. When you start Mac in safe mode then process of automatic disk repair and check executes.
Mac starting in safe boot mode
- If the above method doesn't corrects the error then use the disk utility feature of Mac. 'Disk utility' has the feature to check the file system and then identifies the problem and cures Mac from the problem.
- If disk utility too fails to remove the file system corruption then you can go for the 'fsck' utility.
Single User ModeTo use this, first startup your system in 'Single User Mode' and then type “/sbin/fsck -fy/” in command line prompt. After that click on 'Return', now 'fsck' will do its job and will find if there is any issue in the file system. If issue is found in the file system then it will modify and corrects that problem and returns message:
***** FILE SYSTEM WAS MODIFIED *****
If no issue found then it will return message:
** The volume (name_of_volume) appears to be OK
If 'fsck' shows message that “file system was modified” then keep on doing the same process by typing “/sbin/fsck -fy/” in the command line until 'fsck' returns message that “volume appears to be ok”.
If nothing works then the only solution left is to format your hard drive. But formatting of hard drive will erase all data and the situation becomes worst when you don't have backup to restore deleted data. But still some tools available which can recover all your data after formatting of hard drive in any condition. You can find data recovery software for Mac from some review sites like Top Ten Reviews or you can directly visit http://data-recovery-software-review.toptenreviews.com/mac-recovery-software/